OPTICAL ELEMENT, POLARIZED LIGHT ILLUMINATING DEVICE AND PROJECTION DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical element improved in efficiency for utilizing light by arranging two polarization converting element arrays, with which plural polarized light separating and reflecting planes are alternately arranged through a translucent member, at a prescribed interval so that mutual polarized light separating planes can be confronted. SOLUTION: Polarization converting element arrays 320a and 320b are provided with polarized beam splitter arrays andλ/2 phase difference plates 381 selectively arranged at one part of light emission planes. The polarized beam splitter array is formed by successively sticking plural columnar translucent members 323 respectively having parallelogram-shaped cross sections. A polarized light separating film 331 and a reflecting film 332 are alternately formed on the interface of the translucent member 323. A polarization converting element 350a closest to the optical axis of the polarization converting element array 320a and a polarization converting element 350b closest to the optical axis of the polarization converting element array 320b are oppositely arranged from side to side at an interval Cp. In the interval Cp, dummy parts 370 of the arrays 320a and 320b and a gap Gp thereof are present.